1. Field
The present disclosure is generally related to vacuum molds for molding amorphous alloys.
2. Description of Related Art
Similar to die-casting, injection molding involves heating a material to a molding temperature and forcing such heated material into a mold. Though injection molding speed may be slower than die-casting, common die-casting defects such as blowhole, cold shut, flow line, and misrun still exist in injection molding. These aforementioned defects can be related to air that is trapped within the molding during injection of the material into the die cavity.
Different vacuum die-casting and injection molding processes were developed during the 1980's and 1990's to resolve issues such as these. One type of vacuum that was discussed in vacuum die-casting and injection molding processes is classified as a “low vacuum,” which is defined as having a vacuum pressure above 1 Torr, or, in some cases, above 25 Torr. At this vacuum level, die-casting and injection molding of plastic and metals that are not sensitive to oxygen and nitrogen can be molded. However, casting or molding oxygen and nitrogen sensitive alloys using these technologies, methods, and/or this vacuum generally produces a product of poor or low quality.
For example, amorphous alloy is a new class of material that can be injection molded at lower temperature than its individual constituent. Most amorphous alloys, except precious metal based, are sensitive to oxygen and nitrogen; therefore, they can not be cast or molded using conventional vacuum injection molding methods. Some injection molding machines have molds that are outside the vacuum chamber, which increases the risk of exposure of the amorphous alloy to air (e.g., due to leaks in the mold). Thus, an improved vacuum mold system for injection molding of amorphous alloys when using a system that has a vacuum mold that is outside the vacuum chamber portion of the system can be developed.